The morphological evolution of secondary dendrite arms during coarsening remains poorly understood. In particular, the mechanism governing the fissioning of secondary arms from the main dendrite stem remains controversial. We perform experiments on the International Space Station, since arms that fission from the stem do not sediment and thus can be detected. In addition, it is also possible to follow the morphological evolution of the structure in the absence of convection. Samples were coarsened for different lengths of time from 10 minutes to 48 hours. The morphology of the structure and the number of fissioned arms were determined using three-dimensional reconstructions. The evolution of the microstructure, the change in length scale, number of independent bodies, evolution of the anisotropy of the structure and the interfacial shape distributions as a function of time during coarsening will be discussed.